Mazda 3 Service Manual: Climate Control Unit Inspection [Full Auto Air Conditioner]

Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item (s)

1A

—

—

—

—

—

1B

—

—

—

—

—

1C

+5V

• Driver-side air mix actuator

• Passenger-side air mix actuator

• Airflow mode actuator

• Solar radiation sensor

• Refrigerant pressure sensor*1

Switch the ignition to ON

5

• Related wiring harness

• Driver-side air mix actuator

• Passenger-side air mix actuator

• Airflow mode actuator

• Solar radiation sensor

• Refrigerant pressure sensor*1

• Climate control unit: terminal voltage (1E)

Switch the ignition to Off

1.0 or less

1D

GND

Body ground

Under any condition

1.0 or less

• Related wiring harness

1E

Sensor GND

• Driver-side air mix actuator

• Passenger-side air mix actuator

• Airflow mode actuator

• Evaporator temperature sensor

• Refrigerant pressure sensor*1

Under any condition

1.0 or less

• Related wiring harness

• Climate control unit: terminal voltage (1C)

1F

Solar radiation sensor (RH) input

Solar radiation sensor

Sunlight shined directly on the solar radiation sensor

4

• Related wiring harness

• Climate control unit: terminal voltage (1C)

• Solar radiation sensor

Blocking light to solar radiation sensor

1.0 or less

1G

Potentiometer input

Driver-side air mix actuator

Set temperature at MAX HOT

4.3 or more

• Related wiring harness

• Driver-side air mix actuator

• Climate control unit: terminal voltage (1C)

Set temperature at MAX COLD

1.0 or less

1H

Solar radiation sensor (LH) input

Solar radiation sensor

Sunlight shined directly on the solar radiation sensor

4

• Related wiring harness

• Climate control unit: terminal voltage (1C)

• Solar radiation sensor

Blocking light to solar radiation sensor

1.0 or less

1I

Potentiometer input

Passenger-side air mix actuator

Set temperature at MAX COLD

1.0 or less

• Related wiring harness

• Passenger-side air mix actuator

• Climate control unit: terminal voltage (1C)

Set temperature at MAX HOT

4.3 or more

1J

—

—

—

—

—

1K

Potentiometer input

Airflow mode actuator

VENT

4.3 or more

• Related wiring harness

• Airflow mode actuator

• Climate control unit: terminal voltage (1C)

BI-LEVEL

3.4

HEAT

2.5

HEAT/DEF

1.6

DEFROSTER

0.7 or less

1L

Evaporator temperature sensor input

Evaporator temperature sensor

Compared with temperature detected by evaporator temperature sensor

Refer to graph 1

• Related wiring harness

• Evaporator temperature sensor

• Climate control unit: terminal voltage (1C)

1M

Blower fan speed control

Power MOS FET

Fan stopped

1.0 or less

• Related wiring harness

• Power MOS FET

Fan: manual 1st

2.2

Fan: manual 7th

9.7

1N

Blower motor feedback

• Blower motor

• Power MOS FET

Fan stopped

B+

• Power MOS FET

• Blower motor

• Blower relay

• HEATER 40 A fuse

• Power MOS FET replacement

• Related wiring harness

Fan: manual 1st

9.8

Fan: manual 7th

0.4 or less

1O

—

—

—

—

—

1P

—

—

—

—

—

1Q

Motor operation (COLD)

Passenger-side air mix actuator

Moving towards HOT

1.0 or less

• Related wiring harness

• Passenger-side air mix actuator

Moving towards COLD

B+

1R

Motor operation (FRESH)

Air intake actuator

Moving towards RECIRCULATE

1.0 or less

• Related wiring harness

• Air intake actuator

Moving towards FRESH

B+

1S

Motor operation (HOT)

Passenger-side air mix actuator

Moving towards HOT

B+

• Related wiring harness

• Passenger-side air mix actuator

Moving towards COLD

1.0 or less

1T

Motor operation (RECIRCULATE)

Air intake actuator

Moving towards RECIRCULATE

B+

• Related wiring harness

• Air intake actuator

Moving towards FRESH

1.0 or less

1U

Motor operation (COLD)

Driver-side air mix actuator

Moving towards HOT

1.0 or less

• Related wiring harness

• Driver-side air mix actuator

Moving towards COLD

B+

1V

Motor operation (DEFROSTER)

Airflow mode actuator

Moving towards DEFROSTER

B+

• Related wiring harness

• Airflow mode actuator

Moving towards VENT

1.0 or less

1W

Motor operation (HOT)

Driver-side air mix actuator

Moving towards HOT

B+

• Related wiring harness

• Driver-side air mix actuator

Moving towards COLD

1.0 or less

1X

Motor operation (VENT)

Airflow mode actuator

Moving towards VENT

B+

• Related wiring harness

• Airflow mode actuator

Moving towards DEFROSTER

1.0 or less

2A

Illumination control

Instrument cluster

Headlight switch ON and panel light control switch at MAX

1.0 or less

• Related wiring harness

• Instrument cluster

Headlight switch ON and panel light control switch at MIN

11.5

2B

B+

ROOM 15 A fuse

Under any condition

B+

• Related wiring harness

• ROOM 15 A fuse

2C

—

—

—

—

—

2D

—

—

—

—

—

2E

MS_CAN_H

CAN related module

Because this terminal is for communication, good/no good judgment by terminal voltage is not possible.

• Related wiring harness

2F

TNS signal

TNS relay

TNS ON

B+

• Related wiring harness

• TNS relay

• BCM

• Headlight switch

TNS OFF

1.0 or less

2G

MS_CAN_L

CAN related module

Because this terminal is for communication, good/no good judgment by terminal voltage is not possible.

• Related wiring harness

2H

IG2

HEATER 10 A fuse

Switch the ignition to ON

B+

• Related wiring harness

• HEATER 10 A fuse

Switch the ignition to Off

1.0 or less

2I

—

—

—

—

—

2J*1

Refrigerant pressure sensor input

Refrigerant pressure sensor

Compared with temperature detected by refrigerant pressure sensor

(See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)

• Related wiring harness

• Refrigerant pressure sensor

• Climate control unit: terminal voltage (1C,1E)

2K

—

—

—

—

—

2L

—

—

—

—

—

2M

Passenger compartment temperature sensor input

Passenger compartment temperature sensor

Compared with temperature detected by passenger compartment temperature sensor

Refer to graph 2

• Related wiring harness

• Passenger compartment temperature sensor

• Climate control unit: terminal voltage (2N)

2N

Passenger compartment temperature sensor GND

Passenger compartment temperature sensor

Under any condition

1.0 or less

• Climate control unit: terminal voltage (2M)

2O

—

—

—

—

—

2P

—

—

—

—

—